论文部分内容阅读
生物膜与钝化膜分别可以提高和降低铝土矿细菌溶硅速率.研究了细菌-矿物接触/非触模式下胶质芽孢杆菌HJ07对铝土矿浸出脱硅的影响,分析了浸出过程中铝土矿表面生物膜与钝化膜的形成及对溶硅的影响.结果表明:在铝土矿细菌浸出的前期(0~6d),Al与Si的溶出主要受间接接触模式的影响,铝土矿表面无生物膜与钝化膜形成;在6~12d内,Si的溶出主要受接触模式的影响,Si的溶出速率明显较非接触模式快,12d后,浸出液中SiO2的浓度比非接触模式的高15mg/L左右,铝土矿表面形成了明显的生物膜;在8~12d内,接触模式下Al的溶出速率明显变缓,非接触模式下明显下降,铝土矿表面有Al2O3沉淀产生;12d后,Si的溶出达到浸出终点,而上清液中Al2O3浓度显著下降;细菌代谢产生的胞外聚合物的絮凝作用下,Al2O3沉淀是铝土矿表面钝化的主要原因.生物膜的形成可以促进铝土矿细菌溶硅,Al2O3沉淀所形成的钝化膜对Al与Si的溶出有明显的抑制作用.
Biofilms and passivation films respectively increase and decrease the rate of silicon dissolution in bauxite bacteria.The effect of Bacillus gluconis HJ07 on leaching and desilication of bauxite under bacterial-mineral contact / non-contact mode was studied, and the effects of leaching process The formation of biofilm and passivation film on bauxite surface and the effect on the dissolution of silicon were studied.The results showed that the dissolution of Al and Si was mainly influenced by the indirect contact mode in the early stage of bacterial leaching (0 ~ 6d) In 6 ~ 12 days, the dissolution of Si was mainly affected by the contact mode. The dissolution rate of Si was obviously faster than that of non-contact mode. After 12 days, the concentration of SiO2 in leachate was higher than that of non-contact In the 8 ~ 12 days, the dissolution rate of Al in the contact mode was obviously slowed down, the non-contact mode was significantly decreased, the precipitation of Al2O3 on the surface of bauxite After 12 days, the leaching of Si reached the end of leaching, while the concentration of Al2O3 in the supernatant decreased significantly. Under the flocculation of bacterial extracellular polymers, Al2O3 precipitation was the main reason of surface passivation of bauxite. The formation of bauxite bacteria can promote the dissolution of silicon, Al2O3 precipitation A passivation film formed significantly inhibited the dissolution of Al and Si.